Jitter points to avoid overplotting

Counterintuitively adding random noise to a plot can sometimes make it
easier to read. Jittering is particularly useful for small datasets with
at least one discrete position.

position_jitter(width=NULL, height=NULL, seed=NA)

Arguments

width, height

Amount of vertical and horizontal jitter. The jitter
is added in both positive and negative directions, so the total spread
is twice the value specified here.

If omitted, defaults to 40% of the resolution of the data: this means the
jitter values will occupy 80% of the implied bins. Categorical data
is aligned on the integers, so a width or height of 0.5 will spread the
data so it's not possible to see the distinction between the categories.

seed

A random seed to make the jitter reproducible.
Useful if you need to apply the same jitter twice, e.g., for a point and
a corresponding label.
The random seed is reset after jittering.
If NA (the default value), the seed is initialised with a random value;
this makes sure that two subsequent calls start with a different seed.
Use NULL to use the current random seed and also avoid resetting
(the behaviour of ggplot 2.2.1 and earlier).

See also

Examples

# Jittering is useful when you have a discrete position, and a relatively# small number of points# take up as much space as a boxplot or a barggplot(mpg, aes(class, hwy)) +
geom_boxplot(colour="grey50") +
geom_jitter()